Android boot process, a few questions after screwing up a flash - Android Q&A, Help & Troubleshooting

Hi,
I'm pretty interested in learning a bit about android, but for the moment i have this tablet that i have royally screwed up during my learning curve It's a PORTO 10.1 chinese tablet.
It would freeze up at the boot logo, but after some searchin, a forum member on the internet kindly sent me some .img files that he used to fix the same brand/model of tablet. They are flashed with the Rockchip tool. It's a RK3066 based tablet.
Prior to receiving the files i was trying other ROM's because it was becoming clear that there wasn't a full dump available for this tablet. None of them worked, and the tablet ended up being completely dead as a result. Being completely stupid once more, i formatted the tablet in the Rockchip tool, before realizing and learning that the ROMS don't come with .img files for partitions like userdata or cache etc? So any chances of recovery even if i did find a partial ROM, may have gone. Yes, i am an idiot Well you have to read a lot and make mistakes to learn, right? I've certainly learnt how to backup all of my partitions now in Rockchip tool since then!
Anyway the jist of it is, the tablet is 100%low level erased as far as i know. I've flashed the files that i was given from a guy on gsmforums, and the tablet turns on again, displays the manufacturer logo and then the android boot animation...but thats it. It gets stuck on the android logo animation.
The partitions i know have been flashed and should exist now are:
misc
boot
kernel
recovery
system
backup
The parameters of these partitions do match what they should be for this tablet. The one thing i did do before screwing the thing up was backup the parameter data. It's a shame i didn't backup anything else!
Obviously there are partitions i am missing, such as userdata, cache and maybe some more from what I've read. My main questions are these:
1. Will android hang like this at the logo if it cannot find/mount a userdata partition? or might i see a terminal/errors instead?
2. If i could get into Recovery (which i can't) does a factory reset just quick format the userdata partition, or would it obliterate it and recreate the partition over again and format it?
3. Are there any ways i may be able to recreate my missing partitions, assuming that it the reason why android is now stuck at the logo?
I did attempt to flash a copy of the cache and userdata partitions from another very similar tablet, but it didn't make any difference.
I know a little about what each partition is there for and what they do, i use a linux pc regularly although i am still working my way up from semi-newbie
Knowing how android should react to having no userdata/cache partitions might help me figure out what i need to do to fix this tablet? I am willing to read and learn if someone can tell me where to begin or give me some hints that might answer some of my questions.
Many thanks,
James.

Related

Clear Cache and Data from Stock Recovery

I've seen a number of requests for this functionality and recently it became necessary for one user who had a disabled Home Key to clear cache and data without the use of ClockworkMod. I have reserached two methods to address this issue. These instructions require some familiarity of android, computer and tablet terminology and usage. Feel free to ask for clarifications in comments. Here we go...
Method I - Stock Recovery Command File
Technical: Stock Recovery command file can be used to perform a few additional functions as well as to alter the path to update files. These commands will execute with all privileges available to recovery mode.
Advantages: Very easy to use. Very little technical knowledge required. No third party software is required for use.
Prerequisites: You will need a MicroSD card formatted FAT32 and a method for transferring files from your computer to the MicroSD.
Usage:
1) Prepare a text file named "command" (no file extension) with one of the following commands on a single line. The wipe data command will wipe both data and cache. Wipe cache will wipe cache only.
--wipe_data
--wipe_cache
2) Place the file in a folder named "recovery" in the root directory of your MicroSD card.
3) From a powered down state, insert the MicroSD card into your tablet and boot into recovery by powering it on while holding down the Volume Up key.
4) Allow the command to execute completely then the tablet should reboot (this may not occur automatically depending on firmware installed).
Method II - Updater Script
Technical: The attached "Updater Scripts" perform delete commands (recursively if necessary) on the named directory or file(s). The directories are mounted automatically by the system before the script executes but it could be easily revised to include that step if necessary. The partitioning, formatting and directory structure are left untouched. Only files are deleted.
Advantages: No third party software is necessary for execution. Relatively easy to modify for more surgical precision (i.e. leaving installed apps but clearing possibly corrupted system data). Included example: "Clear Battery Stats"
Prerequisites: You will need a MicroSD card formatted FAT32 and a method for transferring files from your computer to the MicroSD.
Usage:
1) Download the attached archive (ClearData.zip) to your computer.
2) Extract the files to your computer. You should then have a folder named "recovery" (which contains a file named "command") and an additional archive named "update.zip"
3) Place the recovery folder and the update.zip in the root directory of the MicroSD card.
4) From a powered down state, insert the MicroSD card into your tablet and boot into recovery by powering it on while holding down the Volume Up key.
5) Allow the script to execute completely then reboot the tablet (this may occur automatically depending on firmware installed).
This will become handy someday.
Thanks for sharing your knowledge.
You're welcome. One quick note... the new stock recovery adds a menu simiilar to ClockworkMod. These methods will still work since the recovery folder/command file are checked first but it really isn't as necessary any more.
Need Help
Tried both methods above but either way I get to the viewsonic splash with the message "Booting recovery kernel image" in the upper left and it just stays there, stuck there, I left it for a long time to see and it never leaves that screen.
Any ideas?
Me too
I can't get into clockworkmod either. My machine is running faster. I almost hate to mess it more.
lrgche said:
Tried both methods above but either way I get to the viewsonic splash with the message "Booting recovery kernel image" in the upper left and it just stays there, stuck there, I left it for a long time to see and it never leaves that screen.
Any ideas?
Click to expand...
Click to collapse
That's an indication that you may have more serious problems. nvflash will be required. http://forum.xda-developers.com/showthread.php?t=861950
Once done you will likely need to install ClockworkMod and repartition your internal storage.
Loukoebel said:
I can't get into clockworkmod either. My machine is running faster. I almost hate to mess it more.
Click to expand...
Click to collapse
If your tablet boots properly but you can't get into CWM then it probably isn't installed properly (or at all). http://forum.xda-developers.com/showthread.php?t=865245
Keep in mind that CWM is NOT compatible with all ROMs. Make sure the developer for your chosen ROM recommends it before installing it.
Does your method in opening post have to be run from external micro sdcard?
Both methods are performed with an external MicroSD card. They will work from internal also but it is a little more difficult to get the files in place if your tablet is not booting properly.
K J Rad said:
Both methods are performed with an external MicroSD card. They will work from internal also but it is a little more difficult to get the files in place if your tablet is not booting properly.
Click to expand...
Click to collapse
so your method is a simple way to replace one of the main uses of Clockword MOD?--Plus you stay stock more or less.
That is correct. Method II can also be modified to be less intrusive (leave user apps installed) or embedded into update scripts to perform a wipe during new ROM installs.
K J Rad said:
That is correct. Method II can also be modified to be less intrusive (leave user apps installed) or embedded into update scripts to perform a wipe during new ROM installs.
Click to expand...
Click to collapse
Wipe data does what--remove the apps installed?
And the partitions?
Your post is very interesting. It implies that you have a knowledge of the g-tabs partition structure. I have played with Linux off and on for the last 10+ years. When I began, I used Slackware and when you set it up you had to manually create partition tables using fdisk. You were only required to create two - the data partition and a swap partition but it was often recommended that you create several others - one to contain the home directory to prevent users from using all the disk space (in the days of small disks) for example. It appears that there are a lot of partition on the g-tab. Up to now, I have used various wiping tools like clockwork or calkulins wipe all on faith. I would really like to know what all the partitions are and what is in them. I have used terminal to get to the root folder and tried to do an fdisk to display the partitions but try as I might everything remains hidden. It would seem that a script like yours could be adapted to do many things but I would certainly want to understand the structure a little better before I did anything. I have searched and been unable to find that information. Can you point a way for the curious to learn more about the partition structure on the g-tab?
Wish I had a direction I could point you in. What I've found so far has mostly been stumbled upon while looking for something else. What I can tell you is this...
1) When using fdisk in Android you must specify the device to look at. Try something like: fdisk /dev/block/mccblk3 That should list the current partitions as defined by CWM or whatever was used originally.
2) Within one of those partitions in the list generated above are sub-partitions holding the bootloader, system, data, etc partitions. You can see how they're described in the .cfg files in the nvflash restores that are lying about.
lsu205 said:
Wipe data does what--remove the apps installed?
Click to expand...
Click to collapse
Removes user apps and their associated data as well as system related data and settings.
K J Rad - any idea if the partition size can be set with these methods (2048 & 0) in case I can't get clockwork installed?
CodeNamePapa said:
K J Rad - any idea if the partition size can be set with these methods (2048 & 0) in case I can't get clockwork installed?
Click to expand...
Click to collapse
I'm looking for a solution to that problem. Unfortunately these methods still require the ability to get into recovery mode which likely won't work if you're having trouble getting CWM installed.
If, however, you can get into recovery... then it is theoretically possible to create a script that would accomplish that. As soon as I have one I'll be adding it to the mix ;-)
Edit: I've found something I think will work. Will do some testing tonight. It will still require access to recovery.
I wasn't sure if you saw my other post but I am seeing no partition 0 when I NVFlash with a verifypartition.
http://forum.xda-developers.com/showpost.php?p=13059520&postcount=57
I haven't yet but I will. Let's try to keep this thread on topic. Thanks.
More thoughts:
because I went w/ cyan7 is it possible i have a "bad" kernel and that the stock bekit-1105 or the roebeet-3588 files are crashing w/ the kernel in place already?
I know custom ROMs can have a custom kernel applied separately, but I have no idea whether cyan7 loads it's own kernel...
I have yet to try the nvflash_gtablet_46 version, as I see the img files w/in are different from the original 1105 .zip
Also:
read on another thread that part 2 and part 3 aren't loading for other users when doing nvflash - I did notice that it pauses, runs some stuff, then starts loading part 4 through to the last part, then success. - do part 2 and 3 run for you?
edit: I see a 4349 downgrade.zip in another thread for those who got the OTA update but want to go back to stock 3588 prior to jumping off somewhere else - I can't expect that would help me as I can't do squat w/ recovery yet, but could that possibly "reset" any bad kernel problems? - again, I'm just thinking out loud.
This is well outside the scope of this thread but I find some of what you mention interesting so I'll address it and then end any further off topic discussions.
I did not build nor have I ever used Cyan7 so I have no basis for an opinion on the matter other than this... Each ROM comes with a kernel installed so if properly done an nvflash should overwrite any "bad" kernel.
Part2 and Part3 do indeed load, they are just displayed differently than the other Parts. Just minutes ago I flashed down from Mountain Laurel (4349 based with the new bootloader and recovery) with absolutely no trouble. I can, and have, read back those partitions after an nvflash to prove that point.
The 4349 downgrade will only work for you if recovery is working. Having never used it I don't know that it would "reset" the kernel but any subsequent flashing of a new ROM image would.
I am working on a stock recovery solution for partitioning but it isn't likely to help anyone who is stuck in an APX loop. I do have some ideas on what might help for that condition but I haven't been able to get my hands on one for testing and trying to help people here is like being a consulting mechanic for a car repair that's in someone else's shop having work done on it that you're not being told about.
I'll be happy to address any further comments or questions regarding your specific issue in an appropriate thread or via PM. Thanks.

NT8 boot ONLY via SDCard - RESOLVED!

This issue was resolved by Meghd00t's new REPART.IMG file. See this post on that thread: http://forum.xda-developers.com/showpost.php?p=26060323&postcount=151cool:
I have the 8gb model Nook Tablet and (mistakenly) tried to flash CWM & CM7a to the EMMC of my tablet. At that time, there were no warnings about how the internal flash version would brick the NT8.
Now, my tablet will not boot to ANYTHING on the internal memory. I do NOT get the stock "reset" warnings - or even a flash of light. No matter how I try to boot it (with or without cable, with or without the Nook button) or how long I hold the buttons down, it still remains with a BLACK SCREEN.
However, the SDCard will boot properly.
I followed the instructions on this thread ( http://forum.xda-developers.com/showthread.php?t=1515788) precisely to reset the BootData. I did NOT receive any errors. However, it still will not boot internally.
I then tried sigmabeta's process to flash CM9 (http://forum.xda-developers.com/showthread.php?p=25661314) to the internal emmc (which is supposed to work on NT8). The flash process (via SD/CWM) went properly and I did not receive any errors. However, I still cannot get anything to boot (except my SDCards).
If I put my CM7a (bootable) SDCard (http://forum.xda-developers.com/showthread.php?t=1481826) into the NT8, it boots and runs great! Likewise meghd00t's recovery/CWM sdcard boots and runs properly.
I can do ADB & FASTBOOT and I have even done the dd to download my partitions (for backup) and then dd copies from online onto the device's partitions. Still no joy.
However, even after dd'ing a downloaded copy of p5 to the device, ADB still reports my TRUE serial number? It seems that the dd to part5 did not take?
The only other thing that I have found, that seems significant, is the fact that when I am in CWM, I cannot mount the EMMC. I can ADB/shell into the device but that did not allow me to mount the emmc either.
Any ideas how I can get this thing to boot internally? How can I force the device to mount the emmc?
Click to expand...
Click to collapse
If you have tried all the unbrick methods out there with no luck, then throw it to the wall and see it is fixes .
~ Veronica
Final "fix"
lavero.burgos said:
If you have tried all the unbrick methods out there with no luck, then throw it to the wall and see it is fixes .
~ Veronica
Click to expand...
Click to collapse
Not sure that I have tried ALL of them, that is why I am still searching. Also, people come up with new ideas that have not previously been published.
Thanks for all YOUR help. Especially the dd to fix bootdata.
Sure wish someone would come up with a solution for this problem. There seems to be quite a few of us who are looking for answers.
Sent from my Nook Tablet using XDA
I have been reading for a while and I didn’t want to the answer because the answers are already in the Dev. area. I rather have people do some research and learn to solve their own problem rather than listen to someone else that might misled to do something even worse.
NT already has a recovery in place; factory restores (eight failed boot method). Most people do not know this and try something in an environment that they are not familiar with, Ubuntu. If you are using Windows, then you can resolve it in Windows. You do not need to repartition, format, or delete partitions. I have learned that many people like to format things apparently.
The most common problem seems to be; my NT does not turn on or my nook only boot with sdcard. It is not technically true; your NT actually turns on. The backlight just doesn’t turn on because you format/replace the x-loader/bootloader. X-loader loads the bootloader. You know the bootloader work if you see the “n” logo screen. If your NT restart after the "n" logo screen, it mean bad recovery.img/boot.img.
How did this happen? You flash the wrong MLO file to your x-loader, you used an old CWM (experimental one) and formatted your sdcard or you like to format things.
How do I resolve this? First thing is to make a proper CWM sdcard, one with proper partition table. You can compile your own CWM recovery when you compile CM7. Second, flash stock 1.4.2 rom, which contain the latest x-loader, bootloader, boot, and recovery files that works on both 8GB/16GB NT. This will restore your NT to stock android gingerbread.
If you happen to format the rom partition, you need to restore it with a backup and perform the eight failed boot method. This will restore your proper rom partition data along with the stock android. It is all in my thread in the Dev. area.
If you happen to screw up your partition table, obviously this will not help you until you fix your partition table.
Existing solutions
succulent said:
I have been reading for a while and I didn’t want to the answer because the answers are already in the Dev. area. I rather have people do some research and learn to solve their own problem rather than listen to someone else that might misled to do something even worse.
NT already has a recovery in place; factory restores (eight failed boot method). Most people do not know this and try something in an environment that they are not familiar with, Ubuntu. If you are using Windows, then you can resolve it in Windows. You do not need to repartition, format, or delete partitions. I have learned that many people like to format things apparently.
The most common problem seems to be; my NT does not turn on or my nook only boot with sdcard. It is not technically true; your NT actually turns on. The backlight just doesn’t turn on because you format/replace the x-loader/bootloader. X-loader loads the bootloader. You know the bootloader work if you see the “n” logo screen. If your NT restart after the "n" logo screen, it mean bad recovery.img/boot.img.
How did this happen? You flash the wrong MLO file to your x-loader, you used an old CWM (experimental one) and formatted your sdcard or you like to format things.
How do I resolve this? First thing is to make a proper CWM sdcard, one with proper partition table. You can compile your own CWM recovery when you compile CM7. Second, flash stock 1.4.2 rom, which contain the latest x-loader, bootloader, boot, and recovery files that works on both 8GB/16GB NT. This will restore your NT to stock android gingerbread.
If you happen to format the rom partition, you need to restore it with a backup and perform the eight failed boot method. This will restore your proper rom partition data along with the stock android. It is all in my thread in the Dev. area.
If you happen to screw up your partition table, obviously this will not help you until you fix your partition table.
Click to expand...
Click to collapse
Thanks for the info. I do appreciate it and I will be trying some of your suggestions later today when I get home.
One problem (that seems to be easing up a bit) is the fact that few posters distinguish WHICH version of the NT that they are working with. The NT16 "solutions" became the NT8 "problems." It would be great if everyone posted WHICH version they have.
The other issue is (as you stated) when you follow a guide to fix an issue, it CAN mess up your device even worse that it was. Then, you have TWO issues to deal with - rather than just one as before. I am afraid that is where I am now.
One question: You mention "compiling" CWM. Are you referring to the technical term of compiling code into an executible? Or, are you simply referring to the process of putting a working image onto an SDCard? I can do the latter without issue but I have never compiled code.
I do use Ubuntu Linux so many of the Windows driver issues are moot for me. However, I do have a dual boot with XP in on the other side - just in case I need to do some Windows-only stuff.
I really appreciate the help. I am no novice but I am not a developer either. I can usually search, read, try, and work out the problems that I (and other less technical users) experience. That is what my website is all about - translating the really "tech" jargon into everyday language for non-techies to follow. But this one has stumped me (and at least a few others) for the past couple of months.
succulent said:
I have learned that many people like to format things apparently.
Click to expand...
Click to collapse
Sent from my NookTablet using Tapatalk
I've noticed this as well. People really need to do more reading before randomly selecting/flashing things.

Deieted all partition on my SONY S device

Dear community:
I need serious help! I accidentally deleted (not formatted, deleted; it does not exist) the /all partition on my SONY S device. I need to know how to create ALL new partition so I can restore my device. I need to know everything: which tools to use, which commands to do, etc. How this happened: I can't iNSTALL ANY ROM the device , but I can boot BY TWRP. If I need a different recovery to do this, I can replace that. Basically, I just need to figure out how to create a partition, and I can't install ANY ROM as far as I know. Thanks so much!

Meraki MC74 Android Project [HW/SW] [Experience Required][Help][Android System Noob]

Hi all, I am new to the forums and I think that I need some help with a custom android project.
[Background]
I have bought a Meraki MC74, This phone is a VOIP office desk phone that has a nice 7 inch LCD screen that make for a ballin' custom intercom phone/general android device.
Cisco Meraki has dropped support for this phone, so even if I wanted to pay for a subscription, I couldn't. So custom android it is
[So what I know]
I know that the OEM OS is android 4.X.X with a custom Cisco Meraki dialer to do Meraki's cloud mumbojumbo. I was able to use ADB and Fastboot to flash ClockworkMod, and a custom version of Android 4.1.2 to get the device somewhat working. (it had lots of bugs and problems; but it was running android free of the Cisco Dialer!)
I was able to do this with the help of fellow xdadevelopers forum user "andrewmospak" (If you're reading this; I'm the dude from Ebay. And of course, thanks bro for the help so far!)
The storage is on a 4 GB Kingston EMMC.
[What I wanted for an end goal]
I wanted to have an interesting discontinued Meraki Desk phone that runs android and get all the functions of the phone working within android.
I also wanted to expand the storage from 4GB to 32GB. ( involving de-soldering existing EMMC and solder in the bigger EMMC.)
[What caused me to write this]
I would be fine if I wanted to stop there, but I wanted to try to install a GSI of android 9 in place of 4.1.2.
Again, this wouldn't be a big deal but I had to go and screw this up. I tried to resize some of the partitions (namely system to accommodate the bigger image of the android 9 GSI)but I accidentally completely killed the system,cache, and recovery partitions.
So, as one of the first steps of trouble shooting, I went to the hardest solution. The de-soldering of the EMMC.
I reached out to Andrewmospak again and asked for a full system emmc dump to try to flash his working file system to a spare 4GB EMMC to see an example of the file system of a working android EMMC. I received the image and flashed it to a spare Toshiba chip and soldered that to the phone, but I was unable to get the phone to boot into android right away, only able to load up fastboot.
Interestingly, I know that the EMMC is working because fastboot reports the S/N as the S/N of Andrewmospak's device and not the one written on my device.
[What I don't know]
Should some of the partitions on the EMMC not be recognized by Gparted in Debian? Like the User/System and others are partitioned ext4 while others are just not recognized.
Why when trying to flash partitions using Fastboot, wont fastboot recognise a recovery partition. It would just say that the partition just doesn't exist. same story with boot.
[What needs help]
I would like to know why fastboot wont see flashable volumes when using the EMMC dump flashed to another spare Toshiba EMMC, it is clearly there.
I would like to know how to reconstruct a volume to fix missing ones, and the number of partitions android needs to run.
Would I be able to flash an image of my working device to a 32gb emmc and just expand the system and user partitions into that extra space?
I will appreciate all help given to assist me and others that want a working device instead of a paperweight. ogChamp::fingers-crossed:
MOD ACTION:
Thread closed as duplicate. Follow the original HERE

Restoring an android phone back to its original factory state if EMMC corrupted

Is it possible to restore an android phone back to its original factory state if all of its internal EMMC flash memory has become corrupted?
Firstly, I apologise for the verbose way in which I’ve phrased the question. However, there are literally hundreds of guides on the web that misleadingly claim to show how to backup and restore everything on a phone, but which actually do nothing of the sort. So I felt it best to try and be as precise as possible.
When I buy a new PC, the first thing I generally do is to boot into a Linux live USB distribution and save an image of the entire hard disk. This enables me to restore the PC back to its factory state if something goes horribly wrong.
[As an aside, this is a massive pain in the ass to do and shouldn’t really be necessary. But since PC manufacturers stopped providing separate OS install disks with their computers (presumably this is a deliberate Microsoft policy), a disk image has become the only 100% reliable way of restoring a PC back to its factory state when something goes wrong.]
Anyway, I would like to do something similar with my Android phone (which is a Motorola Moto G4). But what is a relatively simple (if time consuming) task in the PC world is proving to be surprisingly difficult in the Android world. What I’ve done to my phone so far is the following:
I unlocked the bootloader, and installed TWRP.
I then booted into TWRP and created a ‘nandroid’ backup.
I assumed this would be enough to enable me to restore it back to a factory state. But I’ve since done some more research, and it turns out that TWRP does not actually allow you to backup all the partitions on the internal flash memory. And at least one of the excluded partitions stores important stuff like the phone’s IMEI number! So whilst a nandroid backup is useful, it is definitely not a backup of the entire phone.
I’ve noticed that there are some guides on how to copy the entire EMMC flash drive (mmcblk0) to an image file. This process seems somewhat similar to how I would take a disk image on a PC. However, no one explains how to flash the image file back to mmcblk0 if the phone gets bricked.
It also throws up some other question that I can’t find definitive answers to. For example, where is the bootloader actually stored? Is it somewhere on mmcblk0, or is it stored on an entirely separate (and hopefully read-only) flash chip in the same way that a PC’s BIOS would be? If it’s the former, then how would you boot the phone if the mmcblk0 chip became entirely corrupted? Also, where is the Android Debug Bridge utility stored? Is that also on the mmcblk0 chip, or somewhere else?
It’s frustrating that, despite hours of googling, I can’t find definitive answers to these fundamental questions. I would be grateful if anyone here could point me in the right direction.
Thnaks in advance.

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